I've been having this issue for quite some time, is quite annoying, and it's not specific to the current version of MacOS or Safari that I am running. FWIW, I'm currently running the latest versions of both (MasOS Sierra)
I have created upward of 50-60 routes in Garmin Connect, but when I browse to the route list, it only shows me the first 20. There is no way to get to the remaining list.
If I Right-click in the route list and "Open Frame in New Tab" or "Open Frame in New Window", I get the full list (i.e. I can navigate to different pages of routes using the paging buttons at the bottom of the list).
Is this a bug or a setting to be changed in Safari?
Thanks in advance for your help.